How can I save an image from a url?

2019-02-19 05:38发布

I'm setting an ImageView using setImageBitmap with an external image url. I would like to save the image so it can be used later on even if there is no internet connection. Where and how can I save it?

4条回答
别忘想泡老子
2楼-- · 2019-02-19 05:41
URL imageurl = new URL("http://mysite.com/me.jpg"); 
Bitmap bitmap = BitmapFactory.decodeStream(imageurl.openConnection().getInputStream()); 

This code will help you in generating the bitmap from the image url.

This question answers the second part.

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虎瘦雄心在
3楼-- · 2019-02-19 05:49

May be its will help someone like me one day

 new SaveImage().execute(mViewPager.getCurrentItem());//calling function

private void saveImage(int currentItem) {
    String stringUrl = Site.BASE_URL + "socialengine/" + allImages.get(currentItem).getMaster();
    Utils.debugger(TAG, stringUrl);

    HttpURLConnection urlConnection = null;
    try {
        URL url = new URL(stringUrl);
        urlConnection = (HttpURLConnection) url.openConnection();
        urlConnection.setRequestMethod("GET");
        urlConnection.setDoOutput(true);
        urlConnection.connect();
        File sdCardRoot = Environment.getExternalStorageDirectory().getAbsoluteFile();

        String fileName = stringUrl.substring(stringUrl.lastIndexOf('/') + 1, stringUrl.length());
        String fileNameWithoutExtn = fileName.substring(0, fileName.lastIndexOf('.'));

        File imgFile = new File(sdCardRoot, "IMG" + System.currentTimeMillis() / 100 + fileName);
        if (!sdCardRoot.exists()) {
            imgFile.createNewFile();
        }

        InputStream inputStream = urlConnection.getInputStream();
        int totalSize = urlConnection.getContentLength();
        FileOutputStream outPut = new FileOutputStream(imgFile);

        int downloadedSize = 0;
        byte[] buffer = new byte[2024];
        int bufferLength = 0;
        while ((bufferLength = inputStream.read(buffer)) > 0) {
            outPut.write(buffer, 0, bufferLength);
            downloadedSize += bufferLength;
            Utils.debugger("Progress:", "downloadedSize:" + Math.abs(downloadedSize*100/totalSize));
        }
        outPut.close();
        //if (downloadedSize == totalSize);
            //Toast.makeText(context, "Downloaded" + imgFile.getPath(), Toast.LENGTH_LONG).show();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

 private class SaveImage extends AsyncTask<Integer, Void, String> {

    @Override
    protected String doInBackground(Integer... strings) {
        saveImage(strings[0]);
        return "saved";
    }

    @Override
    protected void onPostExecute(String s) {
        Toast.makeText(context, "" + s, Toast.LENGTH_SHORT).show();
    }
}
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SAY GOODBYE
4楼-- · 2019-02-19 05:57

you can save image in sdcard and you can use that image in future without internet.

see this tutorial will show how to store image and again read it.

Hope this will help you.....!

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成全新的幸福
5楼-- · 2019-02-19 06:02

You have to save it in SD card or in your package data, because on runtime you only have access to these. To do that this is a good example

URL url = new URL ("file://some/path/anImage.png");
InputStream input = url.openStream();
try {
//The sdcard directory e.g. '/sdcard' can be used directly, or 
//more safely abstracted with getExternalStorageDirectory()
File storagePath = Environment.getExternalStorageDirectory();
OutputStream output = new FileOutputStream (storagePath + "/myImage.png");
try {
    byte[] buffer = new byte[aReasonableSize];
    int bytesRead = 0;
    while ((bytesRead = input.read(buffer, 0, buffer.length)) >= 0) {
        output.write(buffer, 0, bytesRead);
    }
} finally {
    output.close();
}
} finally {
input.close();
}

Source : How do I transfer an image from its URL to the SD card?

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